School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China.
College of Environment and Resources, Southwest University of Science and Technology, Mianyang 621010, China; State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
Sci Total Environ. 2022 Apr 1;815:152856. doi: 10.1016/j.scitotenv.2021.152856. Epub 2022 Jan 5.
Explosive pollutants remaining in global soils are serious threats to human health and ecological safety. Soils contaminated by trinitrotoluene (TNT) and cyclotrimethylene trinitramine (RDX) are simulated in this study and remediated using vetiver grass and effective microorganism (EM) flora to determine the efficacy of combined remediation in reshaping the microenvironment and bacterial community of soils contaminated by explosives. The degradation rates of TNT and RDX after 60 days of combined remediation were 95.66% and 84.37%, respectively. Soil microbial activity and enzyme activities related to the nitrogen cycle were upregulated. The content of soil elements in the remediation group changed significantly. Vetiver remediation increased the diversity and significantly changed the structure of the microbial community. Notably, bacteria, such as Sphingomonadaceae and Actinobacteriota, which can degrade explosives, occupied the soil niche, and the Proteobacteria and Bacteroidota, which are involved in sugar metabolism, showed particularly increased abundance. The metabolism of soil carbohydrates, fatty acids, and amino acids was upregulated in the vetiver, EM flora, and combined vetiver+EM flora remediation groups, and the most significantly upregulated pathway was galactose metabolism. The combined vetiver and EM flora treatment of soil contaminated by explosives greatly improved the ecology of the soil microenvironment.
土壤中残留的爆炸污染物对人类健康和生态安全构成严重威胁。本研究模拟了三硝基甲苯（TNT）和环三亚甲基三硝胺（RDX）污染的土壤，并采用香根草和有效微生物（EM）菌群进行修复，以确定联合修复在重塑受爆炸物污染土壤的微环境和细菌群落方面的效果。联合修复 60 天后，TNT 和 RDX 的降解率分别达到 95.66%和 84.37%。土壤微生物活性和与氮循环相关的酶活性得到上调。修复组中土壤元素的含量发生了明显变化。香根草修复增加了微生物群落的多样性，并显著改变了其结构。值得注意的是，能够降解爆炸物的细菌，如鞘氨醇单胞菌科和放线菌门，占据了土壤小生境，而参与糖代谢的变形菌门和拟杆菌门则表现出特别高的丰度。香根草、EM 菌群和联合香根草+EM 菌群修复组中土壤碳水化合物、脂肪酸和氨基酸的代谢得到上调，其中上调最明显的途径是半乳糖代谢。联合使用香根草和 EM 菌群处理受爆炸物污染的土壤，极大地改善了土壤微环境的生态。
